In general, a file recording apparatus utilizing a DOS (abbreviation of Disk Operating System) file system is known as an apparatus recording multimedia information including information of motion pictures and voices. This conventional file recording apparatus is described with reference to FIG. 18 to FIG. 21.
The structure of a conventional multimedia information recording apparatus is shown in FIG. 18.
A file for storing multimedia information generally includes data (hereinafter referred to as a data body) of a body part of multimedia data and control information for controlling the data body. The data body may be raw data of a voice and a motion picture, or may be data previously coded by a coding technique such as MPEG (abbreviation of Motion Picture Experts Group), for example.
As to the fine where the corresponding multimedia information is stored, the control information includes information such as a file ID for identifying the file, the size of the file, the system of coding applied to the file etc., and information (hereinafter referred to as index information) for accessing the data body at random etc. The control information is arranged on the head part of the file, i.e., the front position (hereinafter referred to as a header position) of the data body, the rear part of the file, i.e., the rear position (hereinafter referred to as a footer position) of the data body, or the intermediate position of the file etc.
At this point, a case where control information is arranged on the header position and the footer position is illustrated, and the control information arranged on the respective positions is referred to as header control information HD and footer control information FD. Further, the overall file is referred to as a multimedia information file. In ASF (abbreviation of Advanced Streaming Format), for example, the information such as the file ID, the size, the applied coding system etc. as to the multimedia information file is included in the header control information HD, and the index information is included in the footer control information FD. ASF is described in detail in Advanced Streaming Format (ASF) Specification (Feb. 26, 1998 Public Specification Version 1.0/Microsoft Corporation).
Referring to FIG. 18, the multimedia information recording apparatus includes a multimedia information input control part 101 inputting multimedia information 100 obtained by photographing and coding processing etc. from an unillustrated front stage part and outputting the same to each part of a rear stage, as well as a header control information generation part 102, a data body generation part 103 and a footer control information generation part 104 generating and outputting the header control information HD, the data body DB and the footer control information FD respectively on the basis of the multimedia information 100 input from the multimedia information input control part 101. The multimedia information recording apparatus further includes respective ones of a header temporary storage area writing part 301, a data temporary storage area writing part 302 and a footer temporary storage area writing part 303 for inputting and temporarily storing output results from the respective ones of the header control information generation part 102, the data body generation part 103 and the footer control information generation part 104, a file storage area writing part 304 for writing all data in a recording medium (not shown) at a point of time when processing of generation and storage of all data terminates in the header control information generation part 102 to the footer temporary storage area writing part 303, a multimedia information file formation part 108 accepting and processing results of processing of the file storage area writing part 304 and a cluster management part 105 managing a write destination of data on the recording medium by the file storage area writing part 304.
At this point, the file is managed every cluster which is a used unit of a storage area on the recording medium with a table referred to as an FAT (abbreviation of File Allocation Table) where management information is stored in the DOS file system or the like. Each cluster may be formed by a plurality of sectors, for managing the file in units of sectors.
The FAT is recorded on the recording medium along with the multimedia information file. In the FAT, information for specifying at least one cluster where data forming the corresponding multimedia information file is stored is stored according to the sequence for forming the file. Therefore, arrangement of a plurality of clusters where the data of the multimedia information file are stored on the recording medium may be physically continuous arrangement, or may be random arrangement.
The cluster management part 105 manages a cluster (hereinafter referred to as an empty cluster) area of the recording medium not written with effective data but in a state capable of writing new data, the so-called empty state. After termination of writing of data in the recording medium by the file storage area writing part 304, the multimedia information file formation part 108 appends information specific to the file system etc. to a series of data stored on the recording medium and completes the formal requirements as the file, while performing generation and updating of the FAT in a file generation stage.
The file storage area writing part 304 monitors the state of a cluster where data is currently written, and when detecting that data is fully written in the cluster and the writing terminates, it posts this purport to the cluster management part 105 and supplies position information indicating the position of the cluster where the writing terminates in the recording medium to the multimedia information file formation part 108. At this point, the information indicating the position of the cluster in the recording medium is referred to as cluster position information.
When receiving the aforementioned notice from the file storage area writing part 304, the cluster management part 105 returns cluster position information of an empty cluster where data must be subsequently written to the file storage area writing part 304. On the other hand, the multimedia information file formation part 108 updates the contents of the FAT on the basis of the position information of the cluster terminating the writing supplied from the file storage area writing part 304. At a point of time when all data are completely written in the recording medium, the file storage area writing part 304 posts the cluster position information of a cluster where data has been finally written to the multimedia information file formation part 108. In response to this notice, the multimedia information file formation part 108 completes the FAT and forms the multimedia information file.
In FIG. 19A to FIG. 19E, states of respective storage areas during generation of data in the multimedia information recording apparatus of FIG. 18 are typically shown. By arrows A in FIG. 19A to FIG. 19C, positions where data are currently written in the respective storage areas are shown. In the multimedia information recording apparatus in the aforementioned manner, the respective ones of the head control information HD, the data body DB and the footer control information FD are generated by the respective ones of the header control information generation part 102, the data body generation part 103 and the footer control information generation part 104, and the respective ones of the information are concurrently written in respective ones of a header temporary storage area E1 (see FIG. 19A), a data temporary storage area E2 (see FIG. 19B) and a footer temporary storage area E3 (see FIG. 19C) on an unillustrated buffer memory area by the header temporary storage area writing part 301, the data temporary storage area writing part 304 and the footer temporary storage area writing part 303. At this point of time, no data are written in a data storage area E4 (see FIG. 19D) having a plurality of clusters C, which is a file storage area on the recording medium, and an FAT storage area E5 (see FIG. 19E).
In FIG. 20A to FIG. 20E, states of the respective storage areas in termination of generation of data in the multimedia information recording apparatus of FIG. 18 are typically shown. In FIG. 21A to FIG. 21E, states of the respective storage areas in file formation in the multimedia information recording apparatus of FIG. 18 are typically shown. When generation of the header control information HD, the data body DB and the footer control information FD terminates in the multimedia information recording apparatus, the states of the respective storage areas become those of FIG. 20A to FIG. 20C. The header control information HD, the data body DB and the footer control information FD written in the respective temporary storage areas are recorded in the file storage area E4 on the recording medium (see FIG. 21D). At this time, an FAT 500 corresponding to the file storage area E4 is generated in the FAT storage area E5 on the recording medium. Thus, the multimedia information file is formed on the recording medium.
In this case, the rearmost end part of the header control information HD and the head part of the data body DB are recorded in one cluster C4, and the rearmost end part of the data body DB and the head part of the footer control information FD are recorded in one cluster C5, as shown in FIG. 21D. The respective ones of the clusters C4 and C5 include boundaries (hereinafter simply referred to as boundaries) shown by arrows B where data of different types are adjacent.
In the multimedia information recording apparatus of FIG. 18, the sizes of the header control information HD, the data body DB and the footer control information FD are unidentified until generation of the respective ones terminates. Therefore, write processing of twice of generating the respective data while temporarily making the same stored in the respective ones of the temporary storage areas E1 to E3 different from the recording medium and writing each generated data in the file storage area E4 of the actual recording medium at a point of time when generation of the respective data is completed and the sizes of the respective data are defined has been performed. Thus, the conventional generation processing of the multimedia information file has been redundant processing. This enlarges loss related to the processing particularly when the size of each data enlarges. Therefore, it is desirable that each data is directly written in the file storage area E4 of the recording medium in the stage where the same is generated.
While the multimedia information recording apparatus of FIG. 18 sets the temporary storage areas E1 to E3 to buffer memory areas different from areas on the recording medium, these temporary storage areas E1 to E3 may be provided on the recording medium depending on limitation of a hardware scale etc. In this case, processing such as movement and copying etc. of data on the recording medium takes place at a point of time when the multimedia information file is finally created. When a recording medium such as a flash memory, for example, slow in writing is utilized, therefore, the processing time extremely lengthens and it is not excellent in practicalness. When the cluster C4 or C5 including a boundary is present in the file storage area E4 as shown in FIG. 21A to FIG. 21E, a process for acquiring an access position (position of the boundary) in the multimedia information file is required in edit processing of dividing the multimedia information file or mutually connecting the same is required and hence the edit processing is complicated and not excellent in practicalness.